title: Sleep dysfunction and thalamic abnormalities in adolescents at ultra high-risk for psychosis.
abstract: BACKGROUND
  Sleep dysfunction is a pervasive, distressing characteristic of psychosis, yet little is known regarding sleep quality prior to illness onset. At present, it is unclear whether sleep dysfunction precedes the emergence of psychotic symptoms, signifying a core feature of the disorder, or if it represents a consequence of prolonged contact with aspects of schizophrenia and its treatment (e.g., medication use or neurotoxicity) or co-morbid symptoms (e.g., depressive and manic symptomatology). The current study examined sleep dysfunction in adolescents at ultra high-risk (UHR) for psychosis, relationships between sleep disturbances and psychosis symptoms, volume of an integral sleep-structure (thalamus), and associations between thalamic abnormalities and sleep impairment in UHR youth.
  
  
  METHODS
  Thirty-three UHR youth and 33 healthy controls (HC) participated in a self-assessment of sleep functioning (Pittsburgh Sleep Quality Index; PSQI), self and parent-report clinical interviews, and structural magnetic resonance imaging (MRI).
  
  
  RESULTS
  UHR adolescents displayed increased latency to sleep onset and greater sleep disturbances/disrupted continuity compared to HC youth, over and above concurrent mood symptoms. Among UHR youth, increased sleep dysfunction was associated with greater negative symptom severity but not positive symptoms. Compared to HC adolescents, UHR participants displayed decreased bilateral thalamus volume, which was associated with increased sleep dysfunction.
  
  
  CONCLUSIONS
  Sleep dysfunction occurs during the pre-psychotic period, and may play a role in the etiology and pathophysiology of psychosis. In addition, the relationship of disrupted sleep to psychosis symptoms in UHR youth indicates that prevention and intervention strategies may be improved by targeting sleep stabilization in the pre-psychotic period.
authors.affiliation: Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO, USA; Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA. Electronic address: jessica.lunsford@colorado.edu.
authors.forename: Jessica R
authors.initials: JR
authors.lastname: Lunsford-Avery
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Orr
authors.forename: Tina
authors.initials: T
authors.lastname: Gupta
authors.forename: Andrea
authors.initials: A
authors.lastname: Pelletier-Baldelli
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Dean
authors.forename: Ashley K
authors.initials: AK
authors.lastname: Smith Watts
authors.forename: Jessica
authors.initials: J
authors.lastname: Bernard
authors.forename: Zachary B
authors.initials: ZB
authors.lastname: Millman
authors.forename: Vijay A
authors.initials: VA
authors.lastname: Mittal
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000150:complications* / Q000473:pathology*; D012307:Risk Factors; D012893:Sleep Wake Disorders / Q000209:etiology*; D013788:Thalamus / Q000473:pathology*; D055815:Young Adult
keywords: Premorbid; Prodromal; Psychosis; Schizophrenia; Sleep dysfunction; Ultra high-risk